%T The mistaken axioms of wireless-network research
%A David Kotz
%A Calvin Newport
%A Chip Elliott
%R Technical Report TR2003-467
%I Dartmouth College, Computer Science
%C Hanover, NH
%D July 2003
%U http://www.cs.dartmouth.edu/reports/TR2003-467.ps.Z
%X
 Most research on ad-hoc wireless networks makes simplifying
 assumptions about radio propagation.  The ``Flat Earth'' model of the
 world is surprisingly popular: all radios have circular range, have
 perfect coverage in that range, and travel on a two-dimensional plane.
 CMU's ns-2 radio models are better but still fail to represent
 many aspects of realistic radio networks, including hills, obstacles,
 link asymmetries, and unpredictable fading.  We briefly argue that key
 ``axioms'' of these types of propagation models lead to simulation
 results that do not adequately reflect real behavior of ad-hoc
 networks, and hence to network protocols that may not work well (or at
 all) in reality.  We then present a set of 802.11 measurements that
 clearly demonstrate that these ``axioms'' are contrary to fact.  The
 broad chasm between simulation and reality calls into question many of
 results from prior papers, and we summarize with a series of
 recommendations for researchers considering analytic or simulation
 models of wireless networks.
%Z
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